fix(gazelle) Delete python targets with invalid srcs

gazelle/python/generate.go

@@ -32,6 +32,7 @@ import (
 	"github.com/emirpasic/gods/sets/treeset"
 	godsutils "github.com/emirpasic/gods/utils"
 
+
 	"github.com/bazel-contrib/rules_python/gazelle/pythonconfig"
 )
 
@@ -225,7 +226,6 @@ func (py *Python) GenerateRules(args language.GenerateArgs) language.GenerateRes
 
 	var result language.GenerateResult
 	result.Gen = make([]*rule.Rule, 0)
-
 	collisionErrors := singlylinkedlist.New()
 
 	appendPyLibrary := func(srcs *treeset.Set, pyLibraryTargetName string) {
@@ -473,7 +473,10 @@ func (py *Python) GenerateRules(args language.GenerateArgs) language.GenerateRes
 		result.Gen = append(result.Gen, pyTest)
 		result.Imports = append(result.Imports, pyTest.PrivateAttr(config.GazelleImportsKey))
 	}
-
+	if !cfg.CoarseGrainedGeneration() {
+		emptyRules := py.getRulesWithInvalidSrcs(args)
+		result.Empty = append(result.Empty, emptyRules...)
+	}
 	if !collisionErrors.Empty() {
 		it := collisionErrors.Iterator()
 		for it.Next() {
@@ -485,6 +488,44 @@ func (py *Python) GenerateRules(args language.GenerateArgs) language.GenerateRes
 	return result
 }
 
+// getRulesWithInvalidSrcs checks existing Python rules in the BUILD file and return the rules with invalid srcs.
+func (py *Python) getRulesWithInvalidSrcs(args language.GenerateArgs) (invalidRules []*rule.Rule) {
+	if args.File == nil {
+		return
+	}
+	filesMap := make(map[string]struct{})
+	for _, file := range args.RegularFiles {
+		filesMap[file] = struct{}{}
+	}
+	for _, file := range args.GenFiles {
+		filesMap[file] = struct{}{}
+	}
+
+	isTarget := func(src string) bool {
+		return strings.HasPrefix(src, "@") || strings.HasPrefix(src, "//") || strings.HasPrefix(src, ":")
+	}
+	for _, existingRule := range args.File.Rules {
+		if existingRule.Kind() != pyBinaryKind {
+			continue
+		}
+		allInvalidSrcs := true
+		for _, src := range existingRule.AttrStrings("srcs") {
+			if _, ok := filesMap[src]; ok {
+				allInvalidSrcs = false
+				break
+			}
+			if isTarget(src) {
+				allInvalidSrcs = false
+				break
+			}
+		}
+		if allInvalidSrcs {
+			invalidRules = append(invalidRules, newTargetBuilder(existingRule.Kind(), existingRule.Name(), args.Config.RepoRoot, args.Rel, nil).build())
+		}
+	}
+	return invalidRules
+}
+
 // isBazelPackage determines if the directory is a Bazel package by probing for
 // the existence of a known BUILD file name.
 func isBazelPackage(dir string) bool {

gazelle/python/testdata/remove_invalid_binary/BUILD.in

@@ -0,0 +1,7 @@
+load("@rules_python//python:defs.bzl", "py_binary")
+
+py_binary(
+    name = "remove_invalid_binary",
+    srcs = ["__main__.py"],
+    visibility = ["//:__subpackages__"],
+)

gazelle/python/testdata/remove_invalid_binary/README.md

@@ -0,0 +1,3 @@
+# Remove invalid binary
+
+This test case asserts that `py_binary` should be deleted if invalid (no source files).

gazelle/python/testdata/remove_invalid_binary/WORKSPACE

@@ -0,0 +1 @@
+workspace(name = "remove_invalid_binary")

gazelle/python/testdata/remove_invalid_binary/keep_binary/BUILD.in

@@ -0,0 +1,5 @@
+py_binary(
+    name = "keep_target_binary",
+    srcs = ["//test/binary:__main__.py"],
+    visibility = ["//:__subpackages__"],
+)

gazelle/python/testdata/remove_invalid_binary/keep_binary/BUILD.out

@@ -0,0 +1,5 @@
+py_binary(
+    name = "keep_target_binary",
+    srcs = ["//test/binary:__main__.py"],
+    visibility = ["//:__subpackages__"],
+)

gazelle/python/testdata/remove_invalid_binary/test.yaml

@@ -0,0 +1,15 @@
+# Copyright 2023 The Bazel Authors. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+---